A variety of approaches have been developed to condition the hair. A common method of providing conditioning benefit is through the use of conditioning agents such as cationic surfactants and polymers, high melting point fatty compounds, low melting point oils, silicone compounds, and mixtures thereof. Most of these conditioning agents are known to provide various conditioning benefits. For example, some cationic surfactants, when used together with some high melting point fatty compounds, are believed to provide a gel matrix which is suitable for providing a variety of conditioning benefits such as slippery feel during the application to wet hair and softness and moisturized feel on dry hair.
There is a need for hair conditioning compositions which provide coloring benefits while providing conditioning benefits. Such coloring benefit is, for example, at least one of the followings: coloring to non-colored hair, color enhancing of colored hair, preventing color fade of colored hair and grey blending.
A variety of attempts has been made for providing both hair coloring and hair conditioning benefits. For example, Japanese Patent Application Laid-open No. H5-43438 relates to a coloring hair treatment containing two types of cationic surfactants, an acidic dye, and the treatment having a pH value of from 1.5 to 4.5. Japanese Patent Application Laid-open No. H5-43438 discloses a coloring hair treatment composition in Example 3 comprising 0.3% of Behentrimonium Chloride, 0.1% of Cetyltrimonium Chloride, 0.1% of Distearyldimonium Chloride, 10% of Behenyl alcohol, and 0.05% of an acidic dye, and the composition having a pH value of 2.2.
There is a need for conditioners containing direct dyes, especially when containing nonionic and/or cationic dyes, to be kept at a higher pH than conditioners without dyes, for providing desirable color shade to hair in a log term period. At a higher pH, due to the reduced decomposition of such dyes, the conditioners can provide better long term stability of the color performance. There may also be a need for conditioners containing direct dyes to be kept at a higher pH than conditioners without dyes, for providing desirable product color from the dyes.
However, it has been surprisingly found that, at a higher pH, some compositions drive product instability such as phase separation and/or color instability which may result in undesirable hair color. It has been also found that such product instability at a higher pH can be observed more in compositions containing a cationic surfactant system comprising mono-long alkyl cationic surfactant and di-long alkyl cationic surfactant, compared to compositions containing mono-long alkyl cationic surfactants and being substantially free of di-long alkyl cationic surfactant.
Based on the foregoing, there remains a need for hair conditioning compositions, especially in compositions containing a cationic surfactant system comprising mono-long alkyl cationic surfactant and di-long alkyl cationic surfactant, which provide conditioning benefits and coloring benefits at a higher pH, together with improved product stability and/or improved color stability.
None of the existing art provides all of the advantages and benefits of the present invention.